Cadillac SRX First Generation Forum - 2004 - 2009 Discussion, Nav System in Cadillac SRX Forums; While we're attempting to crack the system over watching DVD's (done) and using Nav functions while moving, I have another ...
It may be a "legal thing" but it is not required. My Garmin StreetPilot III used to require a user acknowledgement to clear the warning/disclaimer every time. However, newer versions of the firmware now show the disclaimer for a few seconds, and then automatically clear it with NO user action required.
Conclusion: Obviously, their lawyers can demand it, but some sensible person(s) at Garmin probably understand that any remote legal liability is outweighed by the huge annoyance/inconvenience to the user.
Many of such units also allow you to enter an "advanced setup" mode and turn such nags off. There are similar 'hidden' menus within cell phones as well where you can turn off other nagging features such as carrier logo or manufacturer animation.
I don't have a big problem with the warning screen - it's just one quick tap of the screen... it does bug me when I make a quick stop (at a gas station for instance) and need to confirm again at startup.